Squashfs: optimise squashfs_cache_get entry search
squashfs_cache_get() iterates over all entries to search for
block its looking for. Often get() / put() are called for
same block.
If we cache the current entry index, then we can optimise the
subsequent *_get() calls.
Signed-off-by: Ajeet Yadav <ajeet.yadav.77@gmail.com>
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
diff --git a/fs/squashfs/cache.c b/fs/squashfs/cache.c
index ea6e798..af0b738 100644
--- a/fs/squashfs/cache.c
+++ b/fs/squashfs/cache.c
@@ -70,11 +70,15 @@
spin_lock(&cache->lock);
while (1) {
- for (i = 0; i < cache->entries; i++)
- if (cache->entry[i].block == block)
+ for (i = cache->curr_blk, n = 0; n < cache->entries; n++) {
+ if (cache->entry[i].block == block) {
+ cache->curr_blk = i;
break;
+ }
+ i = (i + 1) % cache->entries;
+ }
- if (i == cache->entries) {
+ if (n == cache->entries) {
/*
* Block not in cache, if all cache entries are used
* go to sleep waiting for one to become available.
@@ -245,6 +249,7 @@
goto cleanup;
}
+ cache->curr_blk = 0;
cache->next_blk = 0;
cache->unused = entries;
cache->entries = entries;